This invention relates generally to systems for detecting obstacles and avoiding collisions. In particular, the present invention relates to a collision detection and warning system for an automobile that uses audible alerts to warn a driver of obstacles in the driver's “blindspots” at the rear and sides of the vehicle.
It is often difficult to change lanes while driving because the driver's blindspots at the rear and sides of the vehicle cannot be seen with either the rearview or side mirrors effectively. The rear looking neck movements are difficult for much of today's population, including the elderly, and the movements distract all drivers from looking ahead. A device that would make changing lanes easier and less dangerous would be widely welcomed.
Collision detection systems have been proposed on high-end cars in today's market. While the technology to achieve collision avoidance, problems with cost and convenience have kept this innovation off most new vehicles and virtually all older vehicles.
Some current systems use either a single transmitter located on the vehicle, such as in U.S. Pat. No. 4,450,430, or a single transmitter located at each side of the vehicle, such as in U.S. Pat. No. 4,028,662 and U.S. Pat. No. 5,339,075, to em it sound, light, or electromagnetic radiation waves at a target area. Some systems, such as in U.S. Pat. No. 5,583,495, suggest either a single transmitter or a transmitter on each side of the vehicle. If an object is in the target area, that object will reflect the waves. These systems then detect the presence of the reflected waves to determine if an object is in the target area, and some of the systems can detect the object's speed relative to the driver's vehicle. A warning signal is transmitted to the driver when a danger is sensed. Nevertheless, many of these systems have had difficulties effectively limiting the target area to distances that pose a danger to the driver. Without effectively limiting the target area, systems detect that a danger is posed to the driver when no such danger exists; this can be referred to as a false alarm or a false positive.
Other current systems use scanning transmitters and receivers, such as in U.S. Pat. No. 6,657,581, to obtain more information about the location of objects in the target areas and determine whether an object poses a threat to the driver. These transmitters and receivers act like those mentioned above and poorly limit the target area. However, the multiple readings help to overcome this shortcoming and provide a way to better determine which objects may be dangerous to the driver. U.S. Pat. No. 5,767,793 uses particular configurations of antenna arrays while scanning in order to better limit the target area and eliminate false positives.
The systems in U.S. Pat. No. 6,281,786 and U.S. Pat. No. 6,606,027 use a plurality of sensors to create more target areas and obtain more information. This additional information helps compensate for the general inability to closely limit the target area.
Still other current systems utilize complex circuitry and computer processing to determine the distance of an object from the transmitter, such as in U.S. Pat. No. 5,235,316.
Therefore, it is desirable to have a collision detection and warning system for an automobile that can detect objects in the driver's blindspots or other target areas, is suitable for both new car manufacture and retrofitting existing vehicles, minimizes false alarms, effectively notifies the driver of impending danger, complies with regulations concerning transmitters, and is relatively inexpensive.